Eisenmann race catless: increased torque?

[kyrix1st]

I was running catless x pipe + oem stock rear muffler before, now running catless+ Eisenmann race. Eisenmann race claims 32% better exhaust flow over stock.

What I find interesting is that I've actually noticed:
1. Increased street mpg (from 5km/L to 5.8km/L on street)
2. Increased low end torque
Current engine oil is Redline 10w60 (7:2 0w40 mix), on the heavier side of 10w60 compared to BMW TT10w60 I ran right after changing rod bearings.

Unless my butt dyno is off the charts, increased low end torque usually means a more restrictive exhaust flow. One other possibility might be an exhaust leak of the previous setup, but I find that a bit unlikely since my highway mpg was very good at 12~13km/L with the catless+ stock rear setup.

Could it be that stock rear muffler actually compensates for restrictive primary cats?

[SYT_Shadow]

I think you'd need a before/after dyno to really know.

When exhausts get much louder it changes other things. I drive cars with loud exhausts much harder just to hear the music

[kyrix1st]

Originally Posted by SYT_Shadow

I think you'd need a before/after dyno to really know.

When exhausts get much louder it changes other things. I drive cars with loud exhausts much harder just to hear the music

I will dyno the results of the current setup soon, switch back to all stock for the upcoming emissions test and get it dynoed again to compare results.

On the other hand, probably will end up putting in the secondary cats. Current setup is way too loud a music..

[tdott]

Too many variables, need before and after dyno to quantify results.

[TheRunningDebt]

I just put Active Autowerke test pipes + X pipes with the Eisenmann Race a week ago. I can't tell much of a change in terms of torque, mostly because my ears are bleeding from the noise and I love it.

[that_grey_m3]

Originally Posted by kyrix1st

I will dyno the results of the current setup soon, switch back to all stock for the upcoming emissions test and get it dynoed again to compare results.

On the other hand, probably will end up putting in the secondary cats. Current setup is way too loud a music..

How is the interior noise/drone from your new exhaust set up? Is it tolerable?

[kyrix1st]

Originally Posted by jembry8

I just put Active Autowerke test pipes + X pipes with the Eisenmann Race a week ago. I can't tell much of a change in terms of torque, mostly because my ears are bleeding from the noise and I love it.

It's a bit too much really. I used to enjoy listening to that sonorous S65 in the tunnel. Now I can't hear shiite after I floor the car because my eardrums are blown.

Originally Posted by that_grey_m3

How is the interior noise/drone from your new exhaust set up? Is it tolerable?

Drone is really bad when you are breaking in the exhaust but it gets better over time. If you get the windows up it only drones at exactly 2,000 rpm, Pretty quiet when coasting. It doesn't seem to bother me or my passengers.

I have Vibratechnics engine mounts so I get more NVH than stock, which could be a bit much for some with this exhaust setup. If you are gonna go Eisenmann race I suggest you put resonators in your x pipe and keep stock engine/transmission mounts.

That being said my catless x pipe has a resonator so it did not drone at all when catless+ stock. It was however too raspy with this setup.
Keep the audio down for the video below:

[kyrix1st]

Update: Swapped out x pipe to oem cats to see how it sounds.

It is way too quiet and sounds muffled, almost stock exhaust level. No drone whatsoever when cold, only when the exhaust is warmed up does it sound slightly bassy around 1500~2000 rpm. With windows up, I can hardly hear it.

Seems like HFC/catless is a must to have fun with your E92.